use strict;
use warnings;

use Data::Diver qw( Dive );
use Data::Dumper;

my %h;

# The exists function will autovivify intermediate keys

print "Testing with exists\n";
printf "key1 %s exist\n", exists $h{key1} ? 'does' : 'does not';
printf "key1-key2 %s exist\n", exists $h{key1}{key2} ? 'does' : 'does not';
printf "key1 %s exist\n", exists $h{key1} ? 'does' : 'does not';
print Dumper( \%h );

# Data::Diver's Dive will not autovivify intermediate keys

print "\nTesting with Data::Diver\n";
my @values = Dive ( \%h, 'key3', 'key4' );
printf "key3-key4 %s exist\n", @values ? 'does' : 'does not';
print Dumper( \%h );

##</code><code>##

Testing with exists
key1 does not exist
key1-key2 does not exist
key1 does exist
$VAR1 = {
          'key1' => {}
        };

Testing with Data::Diver
key3-key4 does not exist
$VAR1 = {
          'key1' => {}
        };